The silence of early tradition, as well as of Scripture, concerning the outward form of the Saviour of mankind, seems providentially designed to turn the mind from a sensuous regard for his person to a spiritual apprehension of his saving grace. The spurious epistle of Publius Lentulus, an imaginary contemporary of Christ, which is of uncertain and probably late date, contains the first written portraiture of Our Lord, which already indicates a departure from the generally youthful type of the Catacombs. “His countenance,” says this account, “is severe and expressive, so as to inspire beholders at once with love and fear.... In reproving or censuring, he is awe-inspiring; in exhorting and teaching, his speech is gentle and caressing. His expression is of wonderful sweetness and gravity. No one ever saw him laugh, though he has been often seen to weep.”[585] The oldest extant picture of the head of Christ treated separately is 346 a profile brought from the Catacomb of Callixtus, now in the Christian Museum of the Vatican, and figured in the engraving on the following page. It is in imitation of mosaic, about life-size, and of a different type from the figure of Our Lord in composition in the frescoes and 347 sculptures of the Catacombs. He is portrayed as of adult age, his calm, smooth brow shaded by long brown hair which is parted in the middle and falls in masses on the shoulders. The eyes are large and thoughtful, the nose long and narrow, the beard soft and flowing, and the general expression of countenance serene and mild. This became the hieratic type of many of the noblest pictures of later Italian art, and, according to the Abbé Brivati, inspired the genius of Da Vinci, Raphael, and Caracci. [Illustration: Fig. 106.--The Oldest Extant Picture of Our Lord.] In the Catacomb of Sts. Nereus and Achilles the head and bust of Christ form a medallion in the centre of a vaulted ceiling. The face is of a noble and dignified expression, mingled with benevolence; but it is older in aspect, and probably of considerably later date, than that here given. Kugler, however, claims for it priority of origin. Both of these were probably of the latter part of the fourth century, and were executed not by the Christians of the purest ages of the church, but by those who had begun to walk by sight and not by faith. The primitive Christians, we have seen, had no professed portraits of Christ, but only allegorical representations of the Good Shepherd, or a youthful figure regarded as the abstractions or genius of 348 Christianity. “We must not,” says a Father of the second century, “cling to the sensuous, but rise to the spiritual. The familiarity of daily sight lowers the dignity of the divine, and to pretend to worship a spiritual essence through earthly matter is to degrade that essence to the world of sense.”[586]